[Insecticide resistance mechanisms of Aedes aegypti (Diptera: Culicidae) from two Peruvian provinces].

Insecticide resistance of Aedes aegypti larvae and adults from two Peruvian provinces, that is, Trujillo and Tumbes provinces, was conducted. High infestation indexes and extensive use of insecticides based on the Vector Surveillance and Control Strategy of the Ministry of Public Health prevailed in these places. Larval bioassays revealed susceptibility to organophosphorate insecticide called malathion in TRUJILLO strain, it being moderate to fention and fenitrotion and high to chlorpyriphos and temephos;however, TUMBES strain was susceptible to the evaluated organophosphorate compounds, except for fention, with moderate resistance. In the adult state, at the recommended dose, TRUJILLO strain showed resistence to DDT organochlorate insecticide and to pyrethoids called lambdacyalotrine and cyflutrine whereas TUMBES was resistant to DDT and to all assessed pyrethoids. None of them was resistant to chlorpiriphos in adult stage. By using synergists, the results showed that esterases and monooxigenases played an important role in the detected resistence to organophosphorate in Aedes larvae from TRUJILLO province. Biochemical assays yielded that increased activity of esterases was very frequent in TRUJILLO strain as was the case of glutathion transferase(GST) and modified acetylcholinesterase (AchR). On the other hand, the polyacrylamide gel electrophoresis allowed observing the prevalence of amplified activity of esterases A4 in TRUJILLO strain but not in TUMBES strain.